Original User: crrose
I am having the same error. I am using Workgroup SDE (SQL Server Express 2008) and ArcGIS 9.3.1 with an ArcInfo license. I was on Service Pack 1 during my checkout and editing last week and just upgraded to Service Pack 2 with the QIP also applied today to see if that would make a difference and it didn't.
Basically, I created a Checkout off of a 2 way replica, down to my computer, and had done some editing last week. This week, I opened my saved map document to continue editing and received the above error when I tried to go into an edit session. One of the datasets in my checkout can be edited and one does not show up as existing, although both are in my checkout and I can preview them in ArcCatalog (and my edits from last week are in there). They are versioned and I created them and have permissions, I checked both of these things out. I have attached a Word Document with screenshots and further explanation.